Download Ecology

Ecology
Objectives:
• To understand ecological levels of organization.
• To describe the flow of energy through an
ecosystem.
• To describe and analyze the components of the
water, carbon, nitrogen and phosphorous cycles.
• To identify the effects that destruction of
habitats, pollution, urbanization, and natural
disasters have on population.
What is ecology?
• The scientific study of relationships
between organisms and their environment.
• It explains how living organisms affect
each other and the world they live in.
Why is ecology important?
• Allows us to understand how the natural
world around us works
• Allows us to understand how organisms
(plants & animals) are shaped by their
surroundings (environment)
• Ex. O2 in atmosphere from
photosynthesis.
Ecology Issues Today
• Exploding Human
Population
• 6 billion people in
1996
• 7.8-12.5 billion people
by the year 2050
• Greater Earth
resources necessary
to support humans
• Food, space, energy
The Sixth Mass Extinction
• Human impact has
destroyed the habitats
of many bird species.
• Hawaii, 60 species
now extinct
The Thinning Ozone Layer
• Ozone layer protects
Earth’s living
organisms by
absorbing UV
radiation.
• Hole: low ozone level
over Antarctica
• Sunburns and skin
cancer
Climatic Changes
• Greenhouse Effect: gases in the atmosphere
trap heat emitted from the Earth’s surface,
insulating and warming the Earth
• Burning fossil fuels releases gases that trap heat
in the atmosphere. (carbon dioxide, methane, &
nitrous oxide) As these gases build up, they trap
more heat near the Earth’s surface, causing
Earth’s climate to become warmer than it would
naturally.
Interconnectedness
• Key Theme: All organisms affect and are
affected by the living and non-living
components of their environment
• The next slide shows different species that
are ecologically connected. Describe
some ways they are connected.
How is the environment organized?
•
The parts of an environment are
organized into two categories:
1. Abiotic Factors
2. Biotic Factors
Nonliving Environment
• Abiotic Factors (A=“not” Bio= “living”)–
the nonliving parts of an organism’s
environment (physical and chemical)
• Abiotic factors affect an organism’s life
• Examples:
• Soil, temperature, pH, sunlight
• Precipitation, air currents, and humidity
Living Environment
• Biotic Factors: All the living parts of an
environment
• All organisms depend on others, directly or
indirectly, for food, shelter, reproduction, or
protection.
• Examples: competitors, decomposers, and
predators
Biotic or Abiotic?
• Abiotic
Biotic or Abiotic?
Biotic
Biotic or Abiotic?
Abiotic
Biotic or Abiotic?
Biotic
*Phosphorus
*Calcium
Potassium
*Nitrogen
*Sulfur
Biotic Factors?
Abiotic Factors?
Bacteria live on these roots!
• Bacteria get
carbohydrates
• Plants get the
nitrogen they need to
grow
• These two organisms
depend on each other
for survival
Levels of Organization
• Now that you can identify biotic and abiotic
factors, we will organize their interactions
at different levels
• Ecologists have arranged an organism’s
interactions into different levels according
to complexity.
Levels of Organization
1st Level: Organism
• The simplest level in
ecological organization
• An organism is an
individual living thing.
• Bacterial cell or elephant
• Scientists study the
adaptations that allow
organisms to overcome
challenges of their
environment
2nd Level: Population
• A group of organisms, all
the same species, which
interbreed and live in the
same place at the same
time
• Scientists study the
members of a single
species; how they share
their environment. (Food,
water, etc.)
3rd Level: Community
• Biological Community
is made up of all the
populations of
different species that
live in the same place
at the same time; all
biotic factors
• Here: zebras and
wildebeest
• Scientists study how
the species interact
4th Level: Ecosystem
• All the biotic and
abiotic parts of an
environment found in
a particular place.
• Populations of plants
and animals that
interact with each
other in the same
place and the abiotic
factors of that area.
Ecosystem
• Two Types:
1. Terrestrial (Land)
2. Aquatic (Water)
a. Freshwater (lakes, ponds, rivers)
b. Saltwater/Marine (oceans)
5th Level: Biosphere
• The portion of Earth
that supports life (13
mi. thick)
• Life is found in air, on
land, and in fresh and
salt water
• If the Earth were the
size of an apple, the
biosphere would be
as thick as the apple’s
skin.
Which Level?
• Organism
Which Level?
•
Community
Which Level?
Population
Within an ecosystem
• Species share a habitat (the place where
and organism lives out its life), food and
shelter
• Niche: the way of life of a species; the role
a species plays in its environment.
• Includes all biotic and abiotic interactions
• How a species meets its needs for
– Food and shelter
– Survival and reproduction
Sharing a habitat
Fish, turtles, plants, insects, and birds
• pH, other chemical
factors determines
what lives here.
Amount of sunlight –
source of energy
• Insects and fish eat
plants; turtles eat fish;
birds eat insects
Niche
• All of these finches
have different
sized/shaped beaks.
• Different ecological
niches
Habitat & Niche
The habitat is the organism's "address" and
the niche is its "profession“
Oak Tree?
Predators and Prey
• Predators – seek out and eat other
organisms
• Prey – organisms that are eaten
• Examples?
CAUGHT!
Predation
• Influences where and how a species lives
• Effective way to regulate population
• Predation Defenses: schools of fish, color,
odor
Energy Transfer
• All organisms need energy to grow, move
and reproduce
• In an ecosystem, the ultimate source of
energy comes from the sun
• Plants use that energy to make it’s own
food, and then other organisms eat those
plants to get energy.
Producers
• Organisms that make their own food are
called autotrophs
• Photosynthetic – using the sun to power
food production
• Examples?
• Plants, some kinds of bacteria, protists
(plant-like algae)
Biomass
• The total amount of living matter in a
certain area (habitat).
• Measured in g/m^2
Biomass Pyramid:
Consumers
• Heterotrophs – organisms that cannot make
their own food
Primary Consumer
Secondary Consumer
Tertiary Consumers
Eats plant material
(Rabbits, Cows)
Eat primary
consumers (Foxes,
Hawks, Snakes)
Eat secondary
consumers (Wolves,
Bears, Humans)
Herbivores
• Eat producers (plants)
• Zebra that eat grass
is an herbivore
• Grasshopper
• Caterpillars
Carnivores
• Eat other consumers
• Lions eat zebra
• Praying mantis eats
grasshoppers
Omnivores
• Eat both producers
and other consumers
• Bears eat berries
from a plant
(producer) and also
fish
Detritivores
• Feed on the
“Garbage” of the
ecosystem
• Ex. Fallen leaves and
branches, dead
organisms
• Vultures
Decomposers
• Break down dead
tissues (decay)
• Decay “recycles”
nutrients
How Energy flows through an
ecosystem
• 1st Step Producers
• 2nd Step Primary
Consumers that eat
producers
• 3rd Step Secondary
Consumers that eat
other consumers
• 4th Step Tertiary
Consumers that eat
secondary consumers
What happens to energy as you go up trophic levels? Why?
Tertiary
consumers
10 kcal
Secondary
consumers
100 kcal
Primary
consumers
Producers
1,000 kcal
10,000 kcal
Figure 19.26